The 2011 Census revealed the gap between the two main blocks had decreased from 157,965 to 58,332 in ten years, the equivalent of a reduction of 9,963 per year.
If the trends of the last ten years are to continue, all things being equal, we can calculate the date in which parity is reached.
If the gap is closing by 9,963 per year, it is closing by 27.3 per day (9,963/365). With the gap of 58,332 it will take 2,136 days for parity to be achieved (58,332/27.3).
The Census was carried out on 27 March 2011. 2,136 days on from the this date is 30 January 2017!
Of course people under the age of 18 cannot vote. Excluding under 18s the gap between the main blocks in Census 2011 is 98,561. The gap in the 2001 census was 182,202. Between the last two census' the gap between the two main blocks has decreased by 8,364 per year or 22.9 per day. The gap of 98,561 divided by the change per day gives us 4,301 days. 4,301 days on from 27 March 2011 is 04 January 2023!